net: packet: use seq_hlist_foo() helpers

Simplify seq_file code.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet/af_packet.c

@@ -2510,33 +2510,19 @@ static struct notifier_block packet_netdev_notifier = {
 };
 
 #ifdef CONFIG_PROC_FS
-static inline struct sock *packet_seq_idx(struct net *net, loff_t off)
-{
-	struct sock *s;
-	struct hlist_node *node;
-
-	sk_for_each(s, node, &net->packet.sklist) {
-		if (!off--)
-			return s;
-	}
-	return NULL;
-}
 
 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
 	__acquires(seq_file_net(seq)->packet.sklist_lock)
 {
 	struct net *net = seq_file_net(seq);
 	read_lock(&net->packet.sklist_lock);
-	return *pos ? packet_seq_idx(net, *pos - 1) : SEQ_START_TOKEN;
+	return seq_hlist_start_head(&net->packet.sklist, *pos);
 }
 
 static void *packet_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	struct net *net = seq_file_net(seq);
-	++*pos;
-	return  (v == SEQ_START_TOKEN)
-		? sk_head(&net->packet.sklist)
-		: sk_next((struct sock *)v) ;
+	return seq_hlist_next(v, &net->packet.sklist, pos);
 }
 
 static void packet_seq_stop(struct seq_file *seq, void *v)
@@ -2551,7 +2537,7 @@ static int packet_seq_show(struct seq_file *seq, void *v)
 	if (v == SEQ_START_TOKEN)
 		seq_puts(seq, "sk       RefCnt Type Proto  Iface R Rmem   User   Inode\n");
 	else {
-		struct sock *s = v;
+		struct sock *s = sk_entry(v);
 		const struct packet_sock *po = pkt_sk(s);
 
 		seq_printf(seq,